Drive units of the type mentioned in the foregoing used for actuation of flow-regulating values are known in diverse alternative embodiments in the prior art. In this connection, the following publications may be cited as examples: DE 19540441 A1, WO 2011/095351 A1, EP 2101061 A1, DE 9406760 U1, EP 1418343 A1 and WO 2011/095350 A1.